Blasting gun



Jan. 9

E. HUTTON BLASTING GUN Filed July 24, 1924 NIN Patented Jan. Z6, 1926,

stars BLASTING GUN.

Appleationfled July 24, 1924.

Y To all wzom t Imay concern.:

'l adapted for insertion into a blast hole behind a blasting o rexplosive charge for the purposes of closing the blast hole behind theexplosive charge and of firing or exploding such charge, blasting' gunsof this type l.being especially adapted for use in the blasting of coalin mines.

The primary object yof the present invention is to provide novel andimproved means for packing or tamping the space between the walls of theblast hole and the gun, after the latter has been introduced therein, toprevent Ythe gases under the high pressure produced by the explosion ofthe charge from blowing back along or past the gun, the packing meansprovided by .the present invention enabling' the gun to be easily,quickly' and effectively packed after it has been inserted into the holeand unpacked with the same speed and facility preparatory toits removalfrom the hole.

4Another object of the invention is to provide a novel and improvedsurface on the exterior of the gun, such surface being preferablylocated at a point on the gun between the explosive charge and packingmeans, such surface acting to catch and hold finely divided or powderycoal or material dislodged by the explosion of the charge and thuscausing such material to build up or accumulate and thus lill the spacebetween the wall of the blast hole and the gun, thereby preventing orassisting` in preventing the blowing back along the gun of the gasesprodueedby the explosion of the charge.

To these and other ends the invention consists in certain improvementsand combinations and arrangements of parts all as will behereinaftenmorefully described, the features of novelty being pointed out particularlyin the claims at the end of the specification.

lthe accompanying drawing Figures '1, la and 1b represent axial orlongitudinal sections of the rear, intermediate and forward portions ofla blasting gun erial No, 727,974.

constructed in accordance with the preferred embodiment of the presentinvention;

Figure 2 represents a cross section through the gun taken on the line 22. Figure la; and l Figure 3 is a view similar to Figure 1a, showing thepackino on the gun expanded against the wall of the blast hole.

Similar )arts are designated by the same reference characters in theseveral views.

The present invention is applicable generally to blasting guns of thegeneral class adapted to be inserted into a blast hole which has beenpreviously drilled into the coal or other material to be blasted, behinda blasting charge comprising a suitable explosive, the gun providingmeans for firing or explo-ding the blasting charge. Examples of guns ofthis general class are shown and described in my prior Patent, No.1,241,386, granted September 25, 1917. and my prior pending application,Serial No. 643,078, tiled June 2, 1923. Preferably, the gun serves notonly to effect the firing of the blasting charge, but it also serves topack and close the blast hole, thereby confining the gases resultingfrom the explosion within the blast hole and preventing such gases fromblowing back through the hole and along the gun. The preferredembodiment of the invention is shown in the accompanying drawing andwill be hereinafter described in detail, but it is to be understood thatthe invention is not restricted to the precise construction showin asequivalent constructions are contemplated, and such will be includedwithin the scopeof the claims.

In the present instance, the gun comprises a barrel which may becomposed of one or more sections of tubing of steel or othervmaterial,the vbarrel in the present instance comprising a rear tubular section 1,and a forward section 2, a portion of which is preferably Vreduced i-ndiameter, substantially as shown, and the rear end of the reducedportion of thesection 2 may be threaded into the rear section 1, as at8, or otherwise fixed thereto. The `forward portion of the section 2'has a portion .4 `which is preferably enlarged in diameter so that ithas substantially the same diameter as the rear section 1. The forwardend of the section 4 is -provided with a head 5 which is adapted tooccupy a position immediately adjacent to the blasting Charge in theblasting hole, and it Cil contains means for exploding the blastingcharge. In the present instance, the head 5 is adapted to receive andhold a blasting cartridge which is provided with a socketfor suchpurpose, such cartridge being, for example, of the kind fully shown anddescribed in my application executed of even date herewith. For example,the head 5 may be provided with a threaded projection or boss 6 whichextends forwardly from its forward end and is adapted to enter acorrespondingly threaded socket formed in the base of a cartridge whichcontains the blasting charge, the cartridge being applied to the forwardend of thel gun and the gun then serving as means for inserting andplacing the explosive charge within the blast hole. As shown, thethreaded cartridge receiving projection 6 is formed by the forward endofa plug 7 which is threaded or otherwise fixed within the head 5 on theforward end of the gun. The gun shown in the present instance embodiesmeans for firing blasting charges by percussion, it being understoodthat the blasting cartridges are provided with percussion primers orcaps. Accordingly the plug 7 at the forward end of the gun contains afiring pin 8 which is freely reciprocable in a bore 9 arranged axiallywithin the plug, and the firing pin is provided with a head 10 which mayreciprocate freely, within given limits, in a chamber 11 formed withinthe head 5 immediately in rear of the plug 7. Preferably, va coiledcompression spring 12 surrounds the firing pin 3 and bears against thehead 10 thereon, this spring-serving to normally hold the pin 8 and head10 in retracted position, as shown in Figure 1b, the forward end of thefiring pin being then in retracted position .so that it will not engagethe percussion primer or cap for the blasting charge.

Means is provided for driving the firing pin 8 and its head 10 forwardlywhereby the forward end of the `firing pin will becaused to strike andthereby fire the percussion primer or cap of the blasting charge. Asshown, such means comprises a reciprocatory rod 13 which is arranged`preferably axially within the gun, its forwardendbeing in line with thehead 10 on the firing pin and its rear` end, which is normally containedwithin the rear tubular section 1, may be provided with 'an eye 14 orother suitable means by which a lanyard or other appropriate device maybe attachedto it to retract and then release it, thus allowing it to bepropelled forwardly within the gun, thus causing its forward end todeliver a blow to the firing pin head 10. The means for propelling therod or member 13 forwardly comprises preferably a coiled compressionspring 15 which surrounds the rod 13, and bears at one end against acollar or shoulder 16 which is fixed to the rod 13, the opposite end ofthe spring resting against a guide 17 which may be fixed within thesection 1 by set screws 18 or other suitable means, this guide having acentral opening through which the rod 13 passes and in which this rod isguided. Means is also preferably provided for normally holding the rodor member 13 in such a position that its forward end is out of conn tactwith. the firing pin head 10, so that the latter and the firing pin maybe normally held in inoperative position by its spring 12. The meansemployed for this purpose comprises preferably a coil spring 19 which isof less strength than the spring l5 and bears against the side of thecollar or shoulder 16 opposite to the side thereof engaged by the spring15, the spring 19 resting at its forward end against a suitable fixedstop within the gun, as, for example, the shoulder 2O formed within therear section 1 of the gun by the rear end of the section 2. The spring19 will normally hold the reciprocatory rod 13 in the position shown inFigures 1, 1a.

and 1b, the forward end of this rod being then out of contact with thefiring pin head and hence danger of premature firing of a blastingcharge associated with the gun is minimized or avoided, the forward endof the firing pin being then held by the spring 12 out of contact withthe percussion primer or cap of the blasting charge, and the for# wardend of the rod 13 being held in inoperative position relatively to thefiring pin head. In order to fire the blasting charge, when such isintended, it is only necessary to retract the rod 13 by a lanyard orother device 'attached to its rear end at 14 and to` then trip orrelease the rod in any suitable way, the spring 15 then propelling therod forwardly so that its rod delivers a hammer blow upon the firing pinhead 10, the firing pin being thus driven forwardly in consehole andprevented from blowing back along v the gun and to hold the gun intheblast hole in opposition to the force of the explosion.

The packing means provided byl the present invention is fluid-operatedor controlled,`so that the packing will be easily, qnicklynndeffectively expanded against the wall of the blast hole preliminarily tothe exploding vof the blasting charge, and the packing may be contractedor collapsed with the same speed and facility, after the blasting chargehas sis been exploded, thereby enabling the :gun lto be quickly iremoved'from the blast hole in which the explosion has taken place randinserted in another blast hole. The pack-ing in its preferred form, issl'rown'infthe ,present instance. It comprises preferably -a csleeve 21constructed of a section fof tubing for rulober or j'other `appropriatepliable, flexiblem* elastic material. This tubing 'is -l'ittedver thereduced portion olf the gun fand it preferably has substantially thesame outside diameter as that of the rear vsection 1 and 'the head 5.The ends lof the tube 'or sleere21 are secured to the section 2-of -thegun so that they Vwill have a fluid-tight fitor'joint thereon. Forexam-ple, the exterior of the reduced 'portion 2 of the -gun may b'eformed 'with 'threa'dsror circumferentially eX- tending grooves 22 "atthe points in the length thereof which are immediately with# in the endsof Vthe tubing, and clamping or compressing f'eru'les 23, which arepreferably corrugated, 'as sh'own, are provided to clamp o1' p'ress therespective ends of the slee-ve ortubin'g 21 against the portion 12 ofthe gun, thereby providingfluid-tight 'joints which close the ends ofthe sleeve 21 and prevent leakage oftliuid at the ends of the sleeve.@ne Iof the ferrules 23 may be a'ttached to the portion 4 of the gunwhile the other ferru'le may be attached to a collar 241,. vthe latterbeing fitted on `the exterior of the portion 2 of thevgun and secured inplace thereon in any sui-.table way, as, 'forexample, by the set screws`25. The 4.sleeve or tubing 21 and also the collar 2st may be insertedon the portion 2 of the :gun while 'the latter is detached from the rearsection "1.

The packing` sleeve or tubing 21 enter the drill or blast hole, when thegun is inserted into will freely designated :c the hole, and

means is provided for introducing fluid pressure to the inside of thesleeve or tubing 21 whereby the latter will be expanded and therebyforced outwardly' from the portion 2 of the gun and against the wall ofthe drill or blast hole, substantially as is shown diagrammatically inFigure 3, the pliable, ilexible or elastic properties of the packingsleeve 21 enabling it to conform with or accommodate itself toirregularities in the surface of the wall of the blast hole, therebyinsuring a gas-tight packing of the space between the blast hole and thegun. Preferably, the section 2 of the gun is formed with an axial bore26 which serves as a passageway for the fluid pressure used, and theportion 2 is formed with a suitable number of outwardly extending ports27 which lead from the interior bore. 26 to the exterior of the portion2 or the interior of the packing sleeve 21. lVhen compressed air orother fluid under pressure is introduced into the bore or passageway 26from a hose 28 or other suitable source of supply, such fluid flowslongitudinally along the passageway 26, and then outwardly Vthrough theAports 27Jinto the interior otthepac'king'sleeve and the latter, inconsequence thereof, is expanded; and when the supply of fluid underpressure Fis lcut 'ott and the 'fluid is released or permitted to escapefrom the interior of the packing sleeve, by way 'of the ports 27 andpassageway 26, the packing sleeve is allowed to contract, Ltherebyreleasing tfhe gun in the blast `hole and permitting it to be easily andiquickljyY removed therefrom after the blasting chargeihas beenexploded. Any suitable means may be provided for admitting the fluid'for the purpose of expanding-'the packing preliminarilyfto theexploding vof "the blasting chargeand for 1releasingthe fluid land `thusfallow the lcontraction Lof thepacking after ithe blasting 'charge hasbeen exploded. For example, a valve 29 may fbe provided `on the rearportion fof the gu-n'to control communication between the compressed:air or fluid pressure supply hose 28 and the passageway 26, :andapressure release valve 30 may alsobe provided on Ethe rear portion ofthe girnto allow fluid to be released from Ithe packing ralnd rented tothe atmosphere while fthe .supply valve 29 'is closed. It -Will beunderstood that the release valve 30 'is closed while 'the `sul'iply "uvalve 29 is open, and *viceversa In 'order to 7.allow the`reciprocatorg7 rod or member 13 -to extend throughthe portion '2 -ofthe gun'without lallowing leakageo-filluid from thepassage 26, a liner31 is-preferably litt-ed within the bore 2G for fthe passagetherethrough of the rod 13, the ends of the-liner being expanded or*otherwise fitted asat to provide Huid-tight oints atrthese fpoints.

The presentinvention also providesglneans on the gun for preventing orassisting in preventing the blowing back along the gun of gases producedby the explosion of the blasting charge in the blast hole. Such meanscomprises a surface 33 which is formed preferably on the forward portion4 of the gun, or on that portion thereof which is between the blastingcharge and the packing when such is used. This surface comprisesrelatively shallow closely related alternating ribs and circumferentialgrooves or threads with which the exterior of this portion of the gun isprovided. Such surface serves to catch or hold the linely divided orpowdery coal or other material dislodged by the explosion of theblasting charge, thus causing these particles of material to be built upand accumulate at the points where they are deposited along the lengthof the gun, the accumulated particles filling the space between the gunand the Wall of the blast hole and thus forming, in effect, gas checkswhich prevent or assist in preventing the blowing back of the gasesalong the gun. When a surface of this charlll() acter is used inconjunction with packing means located on the gun to the rear thereof,

the serviceability of the packing is greatly increased, as the packingis protected to a considerable extent from the high pressure gasesproduced by the explosion ofthe blastingl charge.

I claim las my invention 1. A blasting gun comprising a barrel adaptedfor insertion into a blast hole, and a fluid-inflatable packing on theexterior of the barrel and adapted to be inflated and thus expandedagainst the wall of the blast hole.

2. A blasting gun comprising a barrel adapted for insertion into a blasthole, and a uid-infiatablevpacking sleeve surrounding the barrel, thelatter having means for conducting fluid to said packing to inflate andthus expand it. v

3. A blasting gun comprising `a barrel adapted for insertion into ablast hole, and a fluid-inflatable packing surrounding and fixed to thebarrel at a point intermediate in its length.

4. A blasting gun comprising a barrel, a fluid-inflatable packing sleevemounted thereon intermediately of its length, and means forconductingfluid under pressure to the interior of the packing sleeve toinflate and thus expand it.

5. A blastingv gun comprising a barrel, and a fluid-inflatablepacking'sleeve mounted on the exterior thereof, the barrel having meansfor admitting fluid under pressure to the interior of the sleeve toinflate and expand it. p

6. A blasting gun having a fluid-inflatable packing sleeve connected byfluid-tight joints at its ends to the gun, and means for conductingfluid underpressure to the interior of the sleeve to inflate and thusexpand it.

7. A blasting gun having a fluid-inflatable packing sleeve of pliablematerial connected by fluid-tight joints at its ends to the gun, the gunhaving a passage extending longitudinally within it and communicatingwith the interior of the packing sleeve to admit fluid under pressure tothe interior thereof to inflate and thus expand it.

8. A blasting gun comprising a barrel having a passagewayextendinglongitudinally thereof and a port extending outwardlytherefrom, a packing sleeve fitte-d over the exterior of the gun andconnected thereto at its ends, the interior of the packing sleevecommunicating with the outwardly extending port, firing means includinga rod extending lengthwise through said passageway, and a liner whichcloses said passageway at its ends and having a longitudinal borethrough which said rod extends.

9. A blasting gun comprising a barrel having dust-collecting ribsprojecting from its circumference.

lO. A blasting gun comprising a barrel having alternately arrangeddust-collecting projections and indentations on its circumference.

ll. A blasting gun comprising a barrel having packing means locatedYintermediately of its length, and having its exterior surface betweensaid packing means and its forward end formed with 'indentations tocollect and hold material dislodged from a blast hole by a blasttherein.

In testimony whereof I have hereunto set my hand.

ERNEST HUTTON.

